Malicious PDF — malware analysis report

Static analysis result for SHA-256 3553afa2138aa0c7…

MALICIOUS

PDF

77.0 KB Created: 2021-09-02 07:37:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 89d541d14b6a273861473c08c72f8665 SHA-1: c110f97e9cc3a8d69b57d56f4ded413ec7af1170 SHA-256: 3553afa2138aa0c7ddb7c4a6176b428b5cff786e67fc463eaf6cae426ce8bc38
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan payload. It contains a link farm with numerous URLs pointing to various domains, some of which are hosted on compromised WordPress sites or disposable hosting, suggesting an attempt to obscure the final destination. While no scripts were explicitly extracted, the PDF structure and the presence of numerous external links strongly suggest an intent to redirect the user to a malicious site, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://eldorado777.ro/upload/editor/file/sunurobipikekasupefumirud.pdf In PDF document text
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094451bb7775---nikitun.pdfIn PDF document text
    • http://trackeg.com/en/wp-content/plugins/formcraft/file-upload/server/content/files/160b00b9a0068d---77232915322.pdfIn PDF document text
    • http://laduses.nl/image/file/40901062684.pdfIn PDF document text
    • https://floresdeserrezuela.com/aym_image/files/xogirutizupezere.pdfIn PDF document text
    • http://brkvinc.com/userfiles/file/21686609358.pdfIn PDF document text
    • http://livestreaming.group/wp-content/plugins/super-forms/uploads/php/files/6b0ibgoe2a6n6m3933f8f9qf8f1oqfha/jugeno.pdfIn PDF document text
    • http://designklasse.de/ckfinder/userfiles/files/getupafodigopozumob.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160813926b8924---1940398212.pdfIn PDF document text
    • http://vicorsupply.com/uploads/images//files/22522306888.pdfIn PDF document text
    • http://kaies.cn/upfiles/210619101914469994r37ojk.pdfIn PDF document text
    • http://goraku-sangyo.com/userfiles/file/temivugugufopavewudifite.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/fcf4ae33a9cbcb1e3e05234e97a69512/54300335706.pdfIn PDF document text
    • https://thefencedocumentary.ca/adminfiles/file/xevipizeturemozev.pdfIn PDF document text
    • http://w-f-l.de/user_img/file/rozowiloket.pdfIn PDF document text
    • http://zjnep.com/ckeditor/ckfinder/userfiles/files/75043334367.pdfIn PDF document text
    • http://architettodrabeni.it/userfiles/files/93237925847.pdfIn PDF document text
    • https://coolinterier.sk/upload/files/68315027576.pdfIn PDF document text
    • http://voxel-avocats.fr/uploads/file/ropixizoluvuburufiwulutor.pdfIn PDF document text
    • https://bonafideonline.com.ar/wp-content/plugins/super-forms/uploads/php/files/fcf9164e063f68db7e38fb1936cefca1/libetofetozaf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=sna+to+syrPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000caac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAAC 10020 bytes
SHA-256: 3f3aac7ced7f5f34907ba80ae6bccffab383e7a39e156a4bed0868e6839e8da8
font_01_sfnt_off0000e115.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE115 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f927.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF927 17476 bytes
SHA-256: 1fb8b0d137f78c4c4fb597ce22ed6893ce4ee3ba336c0c858d9435c1ed1a7e6f